1911 Encyclopædia Britannica/Ceramics/Technical Methods
Technical Methods.- 425px|thumb|Page731, Volume_05 425px|thumb|Page731, Volume_05 All primitive pottery, whether of ancient or of modern times, has been made by the simplest methods. The clay, dug from the earth's surface, was or is prepared by beating and kneading with the hands, feet or simple mallets of stone or wood; stones and hard particles were picked out; and the mass, well tempered with water, was used without any addition. From this clay, vessels were shaped by scooping out or cutting a solid lump or ball, by building up piece by piece and smoothing down one layer upon another or by squeezing cakes of clay on to some natural object or prepared mould or form. The potter's wheel, though very ancient, was a comparatively late invention, arrived at independently by many races of men. In its simplest form it was a heavy disk pivoted on a central point to be set going by the hand, as the workman squatted on the ground; and it may be seen to-day in India, Ceylon, China or Japan, in all its primitive simplicity (see fig. I). This form of potter's wheel was the only one known until about the Christian era, and then, in Egypt apparently, the improvement was introduced of lengthening the spindle which carries the throwing-wheel and mounting on it near the base a much larger disk which the potter could rotate with his foot, and so have both, hands free for the manipulation of the clay (fig. 2). No further advance seems to have been made before the 17th century, when the wheel was spun by means of a cord working over a pulley; and though a steam-driven wheel was introduced in the middle of the 19th century, this form remains the best for the production of fine pottery. A prevalent misconception with regard to the potter's wheel needs correction. For anythin beyond very simple shapes it is impossible to carry the work to completion on the wheel at one operation as is generally imagined. Ail that the potter can do while the clay is soft enough to “ throw " on the wheel is to get a rough shape of even thickness. This operation completed, the piece is removed from the wheel and set aside to dry. When it is about leather-hard, it may be re-centred carefully on the wheel (the old practice), or placed in a horizontal lathe (since I6th century) and turned down to the exact shape and polished to an even, smooth surface. The Greek vase-makers were already adepts in what is often reckoned a modern, detestable practice. Many Greek vases have obviously been “ thrown ” in separate sections, and when these had contracted and hardened sufficiently they were luted together with slip, and the final vase-shape was smoothed and turned down on the wheel, and even polished to as line a degree of mechanical finish as the modern potter ever attains. So too with the Chinese; many of their forms have been made in two or three portions, subseviluently joined together and finished on the outside as one piece. ndeed, it is remarkable how the Greeks and Chinese had discovered for themselves many devices of this kind which are generally held up to opprobrium as the debased methods of a mechanical age. Page731-2048px-EB1911 - Volume 05 2.djvu.jpg|Fig. 1.-Potter moulding a vessel on the wheel (from a painting in a tomb at Thebes about 1800B.C.). Compare the wheel on the left in fig. 5. FIG. 2.-Potter's wheel of the time of the Ptolemies, moved by the foot (from a wall-relief at Philae). Compare fig. 5, the wheel on the right. Page731-2048px-EB1911_-_Volume_05_5.djvu.jpg|FIG. 3.-Early Greek pottery-kiln, about 700-600 B.c. (from a painted votive tablet found at Corinth, now in the Louvre). The section shows the probable construction of the kiln. Page731-2048px-EB1911_-_Volume_05_6.djvu.jpg|Fig. 4.-Roman kiln found at Castor. The low arch is for the insertion of the fuel; the pots rested on the perforated floor, made of clay slabs; the top of the kiln is missing, -it was probably a dome. 425px|thumb|Page731, Volume_05 425px|thumb|Page731, Volume_05 Always it should be borne in mind that the shaping of pottery by “ pressing " cakes of clay into moulds is much older than the potter's wheel, and has always been the method of making shapes other than those in the round. The modern method of “ casting " pottery by pouring slip, a fluid mixture of clay and water, into absorbent moulds seems to have originated in England about the middle of the 18th century; and this too is a genuine potter's method which does not merit the disapproval with which it has been generally regarded by writers on the potter's art. In all ages the work of the “ thrower ” or “ presser " has been largely supplemented by the modeller, who alters the shape, and applies to it handles, spouts or modelled accessories at will.